scope:

INTRODUCTION

The concept of Net/Near zero energy building (Net ZEB) is now often used and is most of the time included as a specific topic in all the renowned congresses involved in the energy efficiency of buildings (ASHRAE, Clima2010, Eurosun etc.). Despite this, the concept is still generic and there is no harmonized understanding about what is really a Net Zero Energy Building. This is why an international work was started in 2008 within the framework of the International Energy Agency "Towards Net Zero Solar Energy Buildings" (Task40/Annex 52 2008). The objective of this work is to study current net-zero, near net-zero and very low energy buildings and to develop a common understanding, a harmonized international definitions framework (Sartori 2010a), new design tools, innovative solutions sets and industry guidelines. This includes new requirements on comfort and energy performances (Sartori 2010b), the management load matching and grid interaction (Voss 2010) and an exhaustive benchmarking about the existing Net ZEBs already built around the world. There are few Net ZEBs built around the world so far. Very little work is available about the design of Net ZEBs in hot/tropical regions as well. This is why a 3 years programme has been launched in France about this specific topic under the name "EnerPos", French acronym for POSitive ENERgy building.